Duane Foster wrote:
>I'm designing a 16 layer board and would like it to be 'vanilla' (easy to make >- low cost). Is .062" board thickness pretty standard fare for 16 layer? > > Yow! I've never done a 16-layer myself, but have seen a few in other gear. I don't believe I have ever seen 16 layers in a .062" thickness. I think I have seen a number of them run between .1 and .125" thick. I'm guessing that packing that many layers into a very thin total thickness doesn't leave enough room for the core that supports the entire board in the laminating press. "Squirm" is a major problem above 4 layers, as the density variations of the copper layers try to even themselves out by squeezing out of the high-density areas. The only thing to resist those forces are the core(s), which can be one in the center or one just under each outside copper layer. The power/ground planes also help support the laminate just to the side of them. If you need tight layer registration, I think a fabricator is going to have a problem combining that with a thin board. Technique is always improving, of course. Jon ____________________________________________________________ You are subscribed to the PEDA discussion forum To Post messages: mailto:[email protected] Unsubscribe and Other Options: http://techservinc.com/mailman/listinfo/peda_techservinc.com Browse or Search Old Archives (2001-2004): http://www.mail-archive.com/[email protected] Browse or Search Current Archives (2004-Current): http://www.mail-archive.com/[email protected]
